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-rw-r--r--arch/powerpc/platforms/pseries/pseries_energy.c362
1 files changed, 362 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
new file mode 100644
index 000000000..09e98d301
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/pseries_energy.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * POWER platform energy management driver
+ * Copyright (C) 2010 IBM Corporation
+ *
+ * This pseries platform device driver provides access to
+ * platform energy management capabilities.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/device.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <asm/cputhreads.h>
+#include <asm/page.h>
+#include <asm/hvcall.h>
+#include <asm/firmware.h>
+#include <asm/prom.h>
+
+
+#define MODULE_VERS "1.0"
+#define MODULE_NAME "pseries_energy"
+
+/* Driver flags */
+
+static int sysfs_entries;
+
+/* Helper routines */
+
+/* Helper Routines to convert between drc_index to cpu numbers */
+
+static u32 cpu_to_drc_index(int cpu)
+{
+ struct device_node *dn = NULL;
+ struct property *info;
+ int thread_index;
+ int rc = 1;
+ u32 ret = 0;
+
+ dn = of_find_node_by_path("/cpus");
+ if (dn == NULL)
+ goto err;
+
+ /* Convert logical cpu number to core number */
+ thread_index = cpu_core_index_of_thread(cpu);
+
+ info = of_find_property(dn, "ibm,drc-info", NULL);
+ if (info) {
+ struct of_drc_info drc;
+ int j;
+ u32 num_set_entries;
+ const __be32 *value;
+
+ value = of_prop_next_u32(info, NULL, &num_set_entries);
+ if (!value)
+ goto err_of_node_put;
+ else
+ value++;
+
+ for (j = 0; j < num_set_entries; j++) {
+
+ of_read_drc_info_cell(&info, &value, &drc);
+ if (strncmp(drc.drc_type, "CPU", 3))
+ goto err;
+
+ if (thread_index < drc.last_drc_index)
+ break;
+ }
+
+ ret = drc.drc_index_start + (thread_index * drc.sequential_inc);
+ } else {
+ u32 nr_drc_indexes, thread_drc_index;
+
+ /*
+ * The first element of ibm,drc-indexes array is the
+ * number of drc_indexes returned in the list. Hence
+ * thread_index+1 will get the drc_index corresponding
+ * to core number thread_index.
+ */
+ rc = of_property_read_u32_index(dn, "ibm,drc-indexes",
+ 0, &nr_drc_indexes);
+ if (rc)
+ goto err_of_node_put;
+
+ WARN_ON_ONCE(thread_index > nr_drc_indexes);
+ rc = of_property_read_u32_index(dn, "ibm,drc-indexes",
+ thread_index + 1,
+ &thread_drc_index);
+ if (rc)
+ goto err_of_node_put;
+
+ ret = thread_drc_index;
+ }
+
+ rc = 0;
+
+err_of_node_put:
+ of_node_put(dn);
+err:
+ if (rc)
+ printk(KERN_WARNING "cpu_to_drc_index(%d) failed", cpu);
+ return ret;
+}
+
+static int drc_index_to_cpu(u32 drc_index)
+{
+ struct device_node *dn = NULL;
+ struct property *info;
+ const int *indexes;
+ int thread_index = 0, cpu = 0;
+ int rc = 1;
+
+ dn = of_find_node_by_path("/cpus");
+ if (dn == NULL)
+ goto err;
+ info = of_find_property(dn, "ibm,drc-info", NULL);
+ if (info) {
+ struct of_drc_info drc;
+ int j;
+ u32 num_set_entries;
+ const __be32 *value;
+
+ value = of_prop_next_u32(info, NULL, &num_set_entries);
+ if (!value)
+ goto err_of_node_put;
+ else
+ value++;
+
+ for (j = 0; j < num_set_entries; j++) {
+
+ of_read_drc_info_cell(&info, &value, &drc);
+ if (strncmp(drc.drc_type, "CPU", 3))
+ goto err;
+
+ if (drc_index > drc.last_drc_index) {
+ cpu += drc.num_sequential_elems;
+ continue;
+ }
+ cpu += ((drc_index - drc.drc_index_start) /
+ drc.sequential_inc);
+
+ thread_index = cpu_first_thread_of_core(cpu);
+ rc = 0;
+ break;
+ }
+ } else {
+ unsigned long int i;
+
+ indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
+ if (indexes == NULL)
+ goto err_of_node_put;
+ /*
+ * First element in the array is the number of drc_indexes
+ * returned. Search through the list to find the matching
+ * drc_index and get the core number
+ */
+ for (i = 0; i < indexes[0]; i++) {
+ if (indexes[i + 1] == drc_index)
+ break;
+ }
+ /* Convert core number to logical cpu number */
+ thread_index = cpu_first_thread_of_core(i);
+ rc = 0;
+ }
+
+err_of_node_put:
+ of_node_put(dn);
+err:
+ if (rc)
+ printk(KERN_WARNING "drc_index_to_cpu(%d) failed", drc_index);
+ return thread_index;
+}
+
+/*
+ * pseries hypervisor call H_BEST_ENERGY provides hints to OS on
+ * preferred logical cpus to activate or deactivate for optimized
+ * energy consumption.
+ */
+
+#define FLAGS_MODE1 0x004E200000080E01UL
+#define FLAGS_MODE2 0x004E200000080401UL
+#define FLAGS_ACTIVATE 0x100
+
+static ssize_t get_best_energy_list(char *page, int activate)
+{
+ int rc, cnt, i, cpu;
+ unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
+ unsigned long flags = 0;
+ u32 *buf_page;
+ char *s = page;
+
+ buf_page = (u32 *) get_zeroed_page(GFP_KERNEL);
+ if (!buf_page)
+ return -ENOMEM;
+
+ flags = FLAGS_MODE1;
+ if (activate)
+ flags |= FLAGS_ACTIVATE;
+
+ rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags, 0, __pa(buf_page),
+ 0, 0, 0, 0, 0, 0);
+ if (rc != H_SUCCESS) {
+ free_page((unsigned long) buf_page);
+ return -EINVAL;
+ }
+
+ cnt = retbuf[0];
+ for (i = 0; i < cnt; i++) {
+ cpu = drc_index_to_cpu(buf_page[2*i+1]);
+ if ((cpu_online(cpu) && !activate) ||
+ (!cpu_online(cpu) && activate))
+ s += sprintf(s, "%d,", cpu);
+ }
+ if (s > page) { /* Something to show */
+ s--; /* Suppress last comma */
+ s += sprintf(s, "\n");
+ }
+
+ free_page((unsigned long) buf_page);
+ return s-page;
+}
+
+static ssize_t get_best_energy_data(struct device *dev,
+ char *page, int activate)
+{
+ int rc;
+ unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
+ unsigned long flags = 0;
+
+ flags = FLAGS_MODE2;
+ if (activate)
+ flags |= FLAGS_ACTIVATE;
+
+ rc = plpar_hcall9(H_BEST_ENERGY, retbuf, flags,
+ cpu_to_drc_index(dev->id),
+ 0, 0, 0, 0, 0, 0, 0);
+
+ if (rc != H_SUCCESS)
+ return -EINVAL;
+
+ return sprintf(page, "%lu\n", retbuf[1] >> 32);
+}
+
+/* Wrapper functions */
+
+static ssize_t cpu_activate_hint_list_show(struct device *dev,
+ struct device_attribute *attr, char *page)
+{
+ return get_best_energy_list(page, 1);
+}
+
+static ssize_t cpu_deactivate_hint_list_show(struct device *dev,
+ struct device_attribute *attr, char *page)
+{
+ return get_best_energy_list(page, 0);
+}
+
+static ssize_t percpu_activate_hint_show(struct device *dev,
+ struct device_attribute *attr, char *page)
+{
+ return get_best_energy_data(dev, page, 1);
+}
+
+static ssize_t percpu_deactivate_hint_show(struct device *dev,
+ struct device_attribute *attr, char *page)
+{
+ return get_best_energy_data(dev, page, 0);
+}
+
+/*
+ * Create sysfs interface:
+ * /sys/devices/system/cpu/pseries_activate_hint_list
+ * /sys/devices/system/cpu/pseries_deactivate_hint_list
+ * Comma separated list of cpus to activate or deactivate
+ * /sys/devices/system/cpu/cpuN/pseries_activate_hint
+ * /sys/devices/system/cpu/cpuN/pseries_deactivate_hint
+ * Per-cpu value of the hint
+ */
+
+static struct device_attribute attr_cpu_activate_hint_list =
+ __ATTR(pseries_activate_hint_list, 0444,
+ cpu_activate_hint_list_show, NULL);
+
+static struct device_attribute attr_cpu_deactivate_hint_list =
+ __ATTR(pseries_deactivate_hint_list, 0444,
+ cpu_deactivate_hint_list_show, NULL);
+
+static struct device_attribute attr_percpu_activate_hint =
+ __ATTR(pseries_activate_hint, 0444,
+ percpu_activate_hint_show, NULL);
+
+static struct device_attribute attr_percpu_deactivate_hint =
+ __ATTR(pseries_deactivate_hint, 0444,
+ percpu_deactivate_hint_show, NULL);
+
+static int __init pseries_energy_init(void)
+{
+ int cpu, err;
+ struct device *cpu_dev;
+
+ if (!firmware_has_feature(FW_FEATURE_BEST_ENERGY))
+ return 0; /* H_BEST_ENERGY hcall not supported */
+
+ /* Create the sysfs files */
+ err = device_create_file(cpu_subsys.dev_root,
+ &attr_cpu_activate_hint_list);
+ if (!err)
+ err = device_create_file(cpu_subsys.dev_root,
+ &attr_cpu_deactivate_hint_list);
+
+ if (err)
+ return err;
+ for_each_possible_cpu(cpu) {
+ cpu_dev = get_cpu_device(cpu);
+ err = device_create_file(cpu_dev,
+ &attr_percpu_activate_hint);
+ if (err)
+ break;
+ err = device_create_file(cpu_dev,
+ &attr_percpu_deactivate_hint);
+ if (err)
+ break;
+ }
+
+ if (err)
+ return err;
+
+ sysfs_entries = 1; /* Removed entries on cleanup */
+ return 0;
+
+}
+
+static void __exit pseries_energy_cleanup(void)
+{
+ int cpu;
+ struct device *cpu_dev;
+
+ if (!sysfs_entries)
+ return;
+
+ /* Remove the sysfs files */
+ device_remove_file(cpu_subsys.dev_root, &attr_cpu_activate_hint_list);
+ device_remove_file(cpu_subsys.dev_root, &attr_cpu_deactivate_hint_list);
+
+ for_each_possible_cpu(cpu) {
+ cpu_dev = get_cpu_device(cpu);
+ sysfs_remove_file(&cpu_dev->kobj,
+ &attr_percpu_activate_hint.attr);
+ sysfs_remove_file(&cpu_dev->kobj,
+ &attr_percpu_deactivate_hint.attr);
+ }
+}
+
+module_init(pseries_energy_init);
+module_exit(pseries_energy_cleanup);
+MODULE_DESCRIPTION("Driver for pSeries platform energy management");
+MODULE_AUTHOR("Vaidyanathan Srinivasan");
+MODULE_LICENSE("GPL");